1. Technical Field
The present invention relates to a method and apparatus for atomizing a liquid into fine mists. The invention relates in particular to an ultrasonic atomization method and apparatus that is used as an apparatus for atomizing Sake, alcohol used for Sake production, petroleum, crude oil or the like into the mists to obtain a highly concentrated solution as a target substance, or which is optimally used as a humidifier, etc. for atomizing water into the mists to be vaporized into the air.
2. Background Art
The present inventor has previously developed an apparatus for atomizing a liquid containing alcohol into mists, collecting such atomized mists, and separating highly concentrated alcohol (see Patent Document 1). This separation apparatus can, for example, ultrasonically oscillate a starting liquid containing alcohol, atomize the liquid into fine mists to be sent into carrier gas, separate and collect the atomized mists, and separate an alcohol liquid having a higher concentration than the starting liquid. The separation apparatus of this system can separate a highly concentrated alcohol with a small amount of energy when compared with an apparatus in which a starting liquid is heated and vaporized.
In addition, a humidifier ultrasonically oscillating and atomizing water into the mists and vaporizing the atomized mists can humidify the air with a large amount of water and with a small amount of power consumption when compared with a method of heating and vaporizing the water.
In the case of the apparatus for atomizing a liquid into the mists, it is vital how efficiently the liquid can be ultrasonically oscillated and atomized into the mists. This is because the efficiency of atomizing into the mists determines the amount of energy to be consumed, and when the efficiency decreases, the energy consumption increases accordingly. For example, when a lowly concentrated alcohol having been obtained from fermented organic substances is to be separated from water in producing a highly concentrated alcohol, the atomization of water into the mists can be utilized. This is because the lowly concentrated alcohol is atomized into the mists and the atomized mists are collected to obtain a highly concentrated alcohol. The lowly concentrated alcohol is produced by fermentation of organic waste. According to this method, a huge amount of waste can be efficiently utilized to produce a lowly concentrated alcohol. Conventionally, however, the lowly concentrated alcohol is distilled for concentration into the highly concentrated alcohol, which leads to a great amount of energy consumption. Thus, for production of a highly concentrated alcohol, a large amount of energy is consumed in order to utilize the lowly concentrated alcohol being available at a lower cost, which results in an increased cost due to a large amount of energy consumption. It is really important to seek a lower cost process for converting the lowly concentrated alcohol to the highly concentrated alcohol. The method of atomizing the lowly concentrated alcohol into the mists can save energy consumption because the alcohol is not vaporized unlike in the method of distillation. In the process of atomization into the mists, however, it is important to efficiently atomize the lowly concentrated alcohol into the mists.
The apparatus is also used as a humidifier for ultrasonically oscillating water into the mists. For this humidifier as well, it is important to increase the efficiency of atomizing into the mists by the ultrasonic oscillation in order to achieve efficient humidification with smaller electrical consumption.
When the liquid is ultrasonically oscillated upwardly from the bottom by the oscillation apparatus, a liquid column P is generated on the liquid surface W, as shown in FIG. 1, where the liquid is atomized. The inventor has developed an apparatus and method for atomizing a liquid into mists in accordance with such ultrasonic atomization method (refer to Patent Document 1).